Secondary bone marrow graft loss after third-party virus-specific T cell infusion: Case report of a rare complication

Virus-specific T cells (VST) from partially-HLA matched donors have been effective for treatment of refractory viral infections in immunocompromised patients in prior studies with a good safety profile, but rare adverse events have been described. Here we describe a unique and severe adverse event of VST therapy in an infant with severe combined immunodeficiency, who receives, as part of a clinical trial (NCT03475212), third party VSTs for treating cytomegalovirus viremia following bone marrow transplantation. At one-month post-VST infusion, rejection of graft and reversal of chimerism is observed, as is an expansion of T cells exclusively from the VST donor. Single-cell gene expression and T cell receptor profiling demonstrate a narrow repertoire of predominantly activated CD4+ T cells in the recipient at the time of rejection, with the repertoire overlapping more with that of peripheral blood from VST donor than the infused VST product. This case thus demonstrates a rare but serious side effect of VST therapy.

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Flow cytometry: Flow cytometry data was analyzed with FlowJo X (FlowJo LLC, Ashland, OR).Single cell sequencing: 10x data was analyzed using the Seurat package (v (v 4.1.0)for R (v (v 4.1.2).Immunarch (v0.6.6)package for R was used to to measure TCR sample diversity, clonality, and overlap.VDJ junction mapping and clonotype assembly and annotation using the assembled contigs from migec was done with mixcr (v3.0.13) using the analyze amplicon routine.

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The datasets generated during and/or analyzed during the current study have been enclosed in supplemental data.These flow cytometry and single cell sequencing data sets are available on Zenodo under the following link: https://doi.org/10.5281/zenodo.10028505.Single cell sequencing data is also accessible under Genbank (Bioproject PRJNA1051284) All remaining data is enclosed within the article, supplementary information, and source data files.
This study involved evaluation of a female subject, the male bone marrow donor, a female T cell donor, and two male family members of the female T cell donor.All subjects provided informed consent for participation in this study.Studies of H-Y specific antigens may have gender-specific impact on immunologic risks in transplantation.All other studies performed should not be impacted by sex and gender.
This is a study of a rare adverse event that occurred in a single infant with severe combined immunodeficiency.We do not report on race/ethnicity or other socially relevant groupings.
This is a study of an infant with severe combined immunodeficiency (female, age 6 months), her adult bone marrow transplant donor (male, age 27 years), and the utilized adult T cell donor (female, age 47 years).
The subject was recruited on the ACES study (NCT03475212).Eligibility criteria for this study were: patients with primary immunodeficiency or recipients of allogeneic hematopoietic stem cell transplantation with refractory infection with CMV, EBV, or adenovirus, and no other uncontrolled infections, high grade graft versus host disease, or relapse of malignancy.As a pediatric study, subject were limited to those 0-25 years of age.Patients of all genders and ethnicities were eligible for enrollment, with actual subject enrollment limited only by the patient demographics of the 22 centers participating in this study.The study protocol is attached in Supplemental Data.
This study was approved at institutional review boards of participating centers (Children's Hospital of Los Angeles, Children's National Hospital, St Jude's Research Children's Hospital, and Children's Hospital of Atlanta) as well as the drug safety monitoring board of the Pediatric Transplantation and Cellular Therapy Consortium (PTCTC).
The assays performed in this study were primary descriptive in nature as they pertain to only the patient, her BMT donor, and the adult virusspecific T cell (VST) donor.As such, no sample size calculations could be performed, they were limited to available samples from the study patient, BMT donor, and VST donor, all of which were utilized as detailed in the manuscript.
No data was excluded from this manuscript.
All immunoassays were performed in replicate (triplicate where cells allowed) in order to ensure result accuracy.All replicates were successful, and raw data is included in the manuscript appendices.Single cell sequencing was performed on very limited subjects samples, and therefore replication was not possible for these assays.
As a single-subject analysis, randomization was not performed.